Graphite intercalation compounds: A simple model of Fermi surface and transport properties

A parametrized model of the $\pi$ bands of $n$-layer films of graphite is developed for the purpose of studying the Fermi-level properties of graphite intercalation compounds. Specifically, the charge transfer, the density of states, and the conductivity tensor as a function of magnetic field are considered. The first two quantities are proportional to the de Haas-van Alphen frequency and cyclotron mass, respectively. A numerical study is carried out for a single layer of graphite as a function of excess charge. It is shown that the anisotropic dispersion of the energy bands causes unusual galvanomagnetic behavior at small magnetic fields, such as a nonzero magnetoresistance mobility for moderate intercalant concentrations and also a change in the sign of the low-field Hall coefficient at high intercalant concentrations.